洗涤冷却室液池内气液流动特性的模拟研究

STUDY ON SIMULATING CHARACTERISTICS OF GAS-LIQUID FLOW IN LIQUID CISTERN OF THE SCRUBBING-COOLING CHAMBER

为了更好地揭示水煤浆气化炉洗涤冷却室内合成气体穿越液池的多相流动特性,运用流体体积模型对顶部浸没气体射流过程进行了动态模拟,详尽分析了在不同气流速度和不同突扩比下的流场形态、演化过程以及该过程的流动特性,并将计算结果与试验结论进行了对比。研究结果表明:该过程是一个突扩的、存在逆压力梯度和负浮力的顶部浸没气体射流流动过程;气体的最大冲击深度与气体出口动量通量之间呈幂函数关系;随着突扩比的减少,合成气对液池内水的扰动加强,液滴和气泡增多,液面升高。计算结果与试验结果一致。

In order to more better reveal the multiphase flow eharacteristics of synthetic gas passing through the liquid cistern in scrubbing - cooling chamber of a coal - water slurry gasifier,a dynamic simulation of gas jet flow process with submerged top has been carried out by using the liquid volume model, and the flow characteristics of flow field state, the developing process and the process proper under different air flow velocity and different sudden expansion ratio being analysed in detail. A comparison of the calculated result with the tested result has been carried out, results of study show that;the process is a flow process of top- submerged gas jet flow with negative buoyance, adverse pressure gradient, and sudden expansion; the power function relation is existing between the maximal penetration depth of gas and the momentum flux at the gas outlet;along with decrease of the sudden expansion ratio, the synthetic gas is strengthened, the amount of liquid drops and air bubbles being increased, and the liquid level being enhanced. The calculated result tallies well with that of experiment.